Medium and long term follow-up of bilateral atlantoaxial joint screw combined with atlas lamina hook fixation and bone graft fusion in reducible atlantoaxial dislocation

English Keywords:Atlantoaxial dislocation  Transarticular screw  Atlas lamina hook  Fixation  Bone graft fusion

English Abstract:

  【Abstract】 Objectives: To evaluate the medium and long term surgical outcomes of bilateral atlantoaxial joint screw combined with atlas lamina hook fixation and bone graft fusion technique in patients with reducible atlanto-axial dislocation. Methods: A retrospective study was conducted to evaluate the clinical outcomes of this modified therapy in 85 patients. 21 male patients and 64 females were involved, aging 25-65(44±9.4) years old. Diagnoses included atlas fracture(19 cases), atlantoaxial rotatory dislocation(16 cases), odontoid fracture(26 cases), OS(15 cases), atlas of rheumatoid arthritis(9 cases). The clinical outcomes with Ranawat grading, neck disability index(NDI), and visual analog scale(VAS) score for neck pain were evaluation. The following imaging data were evaluated: atlanto-dental interval(ADI), space available for cord(SAC), C1-2 angle, C2-7 angle, bone fusion rate. Results: All the patients completed at least 5 years of follow-up, 95% of the cases with cervical and suboccipital pain improved in Ranawat grading after surgery. Their VAS scores for neck pain decreased by about 5 points(7.56±1.03 to 2.53±0.53, P<0.05). The mean score of NDI was reduced from preoperative 34.76±5.45 to postoperative 13.13±1.21(P<0.05). The ADI was reduced from preoperative 6.5±1.0mm to postoperative 2.4±0.9mm(P<0.05). The mean SAC was increased from preoperative 13.37±2.11mm to postoperative 19.93±2.20mm(P<0.05). The mean C1-2 angle was 21.9°±1.2° before surgery and 26.6°±6.9° at latest follow-up. The mean C2-7 angle was 19.8°±9.2° before surgery and 15.5°±5.9° at latest follow-up. Solid bone fusion was achieved in 81(95.3%) patients. Conclusions: The results of medium and long term follow-up show that bilateral transarticular screw combined with atlas laminar hook fixation and bone graft fusion is reliable and safe in the treatment of reducible atlantoaxial dislocation.